这一句英语语法是否正确?

这一句英语语法是否正确?
请告诉我某某来北京时,需要预订酒店的时间?
Pls tell me 人名 come to BJ,need the time subscribing to a hotel.

你是问某人来的时间还是逗留的时间?
如果是问某人来的时间,好让你预订房间,就用：
Pls tell me the date of XXX's arrival in Beijing in order to make the reservations.
要很简单很简单的,就
Pls tell me when XXX is coming,then I can make the reservations.
如果需要某人逗留的长度,就用：
Pls tell me how long XXX will stay in Beijing,后面同上.